Molecular responses of Erwinia amylovora to low temperatures in oligotrophic conditions

摘要

The plant pathogen Erwinia amylovora causes fire blight, a devastating disease of pome fruit trees. Previous studies of our group showed that temperatures lower than the optimal for growth favor the persistence of E. amylovora starved cells in a culturable state, suggesting adaptations of this pathogen to low temperatures. In this work we have analyzed the expression of genes encoding for 'cold-shock proteins' (CSPs) (cspA, cspD and cspE) and proteins related to cold acclimation (CAPs) and/or other stresses (dps, fliD, katA, katG, rpoS) in E. amylovora cells starved at 20 °C and 4 °C. Gene expression was analyzed by semi-quantitative.reverse transcription (RT)-PCR, using 16S rRNA gene as internal control. According to our initial results CSPs were induced at 20 °C and 4 °C, but only cspD and cspE did it at 4 °C. From the remaining genes, none of them were induced at 20 °C and only dps and katA were induced at 4 °C. The present results suggest the possible contribution of some of the analyzed genes to the adaptation of E. amylovora to low temperatures under oligotrophic conditions resembling those found in natural settings.